Electrical Characterisation of Metal Contacts to 4H-Sic Enhanced by Pre-Metalisation Surface Treatment

4H-SiC substrate samples were etched on the surface in order to alter the surface stoichiometry, to make the surface carbon rich using solutions of HF/Ethyl Glycol and HF/H 2 O. The samples were inspected with AFM, XPS, Raman and electrically (current - voltage) tested by applying probes across two contacts each sample. The results show that in comparison to the unetched samples, the current through the etched samples is approximately two times larger in the HF/EG etched sample and approximately twenty times higher in the HF/H 2 O etched sample. The experiment shows that selective etching has altered the surface electrical conductivity, surface roughness selectively removed silicon atoms leaving a carbon rich surface.